Ventilating system for garages and similar enclosed spaces

ABSTRACT

The system embodying the invention is employed to cool the interior of a normally closed area such as a garage or storage area, and/or to remove any noxious fumes or undesirable odors from inside the garage by moving outside air into the garage and providing means for that inside air and the fumes or odors in it, if any, to be removed to the outside ambient atmosphere. The system includes one or more fans installed in the upper section of the garage door, and the garage door is opened or closed by moving it in any well-known manner either by rolling it&#39;s hinged panels upward to a horizontal position from its normally-closed vertical position, or, when it is a solid door, tilting the entire garage door so that it is substantially horizontal instead of vertical and is located above the garage floor a sufficient distance to drive vehicles that will fit into the garage though the door opening. Those fans have a power cord that extends from a power supply position generally near the garage door opener that is secured to the garage ceiling and powers the garage door from its closed position to its open position, and vice versa, and that power cord is also secured to the garage door in the vicinity of the fan or fans used to move air into and out of the garage when the garage door is closed. The power cord is spring-urged to minimize its relatively free section between the power source and the place where it is secured to the garage door in the vicinity of the fan or fans where it provides power to the fan motor or motors when desired and appropriate. In the preferred embodiment the power cord is wound on a reel that is spring loaded to urge the reel in the rotational direction to wind the part of the power cord that is between the reel and the fan motor or motors, keeping the relatively free section of the power cord in tension so that it does not form any dangerous hanging loops when the garage door is moving from its open position to its closed position. There are also lesser desirable alternatives to apply a spring-loading to the power cord to keep it sufficient tension that it does not form such loops when the garage door is being opened.

Priority of filing date is hereby claimed based on the U.S. provisionalpatent application Ser. No. 60/981,941, filed on Oct. 23, 2007, by thesame inventor as the inventor named in this patent application, andentitled, “Vent-A-Garage.”

BACKGROUND OF THE INVENTION

The following U.S. patents are of sufficient interest to include them inthe background of the invention herein disclosed and claimed. None ofthem disclose the invention herein claimed. However, they show variousdevelopments in the field of garage ventilation over many years, and arelisted in numerical order, with at least the last name of thefirst-named inventor when there are two or more co-inventors listed, andthe issue date of that patent:

1,959,918--Hochbaum. Issued May 22, 1934 2,084,807-Hueglin. Issued Jun.22, 1937 4,175,418-Steffin and Bollwitt Issued Nov. 27, 19795,215,498-Wong and McGibbon Issued Jun. 1, 1993 5,626,288-Huber IssuedMay 6, 1997 5,846,127-Kile Issued Dec. 8, 1998 5,947,814-Czeck et alIssued Sep. 7, 1999 5,976,009-Achen Issued Nov. 2, 1999 6,010,399-Lee etal Issued Jan. 4, 2000 6,036,595-Vole Issued Mar. 14, 20006,326,882-Chin and Lin Issued Dec. 4, 2001 6,386,969-O'Brien Issued May14, 2002 6,958,010-Reese Issued Oct. 25, 2005 6,979,260-Lin Issued Dec.27, 2005

In addition to the above patents, there were other patents and publishedpatent applications that were cited in a search that was made prior tothe filing ofthe above-noted provisional application, all of which wasdone under the auspices of a different patent attorney. None of thesewould have been cited at this time, but are identified here only becausethat search was a part of the earlier development of the background ofthe invention:

4,770,087-Danley et al Issued Sep. 13, 1988 7,169,038-Vignau Issued Jan.30, 2007 (filed Apr. 08, 2003) 2006/0061313-- Filed Sep. 30, 2005.Published Mar. 23, 2006 Fitzgibbon et al. 2006/0289127-Fowler. FiledJun. 24, 2005. Published Dec. 28, 2006.

1. Field of the Invention

The invention relates to the ventilation of enclosures, such as but notlimited to, garages that are usually closed so as to admit a minimalamount of ambient atmospheric air and tending to retain odors, vapors,and hot air therein when closed. There are many types of enclosures ofthat type which would be substantially improved by ventilating them inaccordance with the invention herein disclosed and claimed. It is hereindisclosed as being for a garage, but it is understood that it can alsobe applied to other enclosures such as storage rooms, closets, and workareas where there is a likelihood that heat sources may be locatedtherein that would raise the temperature of the air in the inclosurebeyond that which is desirable. It also relates to the control ofcertain power cords that can at times otherwise be sufficiently loose orfloppy to form loops that may be located in places where they aredangerous.

2 Description of the Related Art

There are numerous patents found primarily or secondarily in the U.S.Patent and Trademark Office Class 454 relating to the general subject ofventilation of certain spaces, commonly being primarily for ventilatinggarages. Some typical ones in that Class include the patents listedabove under the Background of the Invention.

U.S. Pat. No. 6,534,181—Wasson, issued Feb. 25, 2003, classified in U.S.Class 434, Subclass 495, and entitled, “Garage Venting Device,” is themost typical in relation to the invention herein disclosed and claimed.It shows a garage door 1 having two exhaust fans 5 and 8 installed inthe upper part of that door. There are movable louvers between the fanblades and the exterior which are arranged to be opened when the fan isblowing air from the interior of the garage to the outside. Theinvention herein disclosed and claimed does not require louvers. Agarage door opener 6 is also shown, and it is connected with the upperend of the door 1 so that, when it is actuated while the door is closed,it applies a force to the upper end of the garage door to move the doorupwardly and inward as each of the several hinged door sections isguided to be moved from a vertical position to a horizontal position.The door stops its upward and inward movements once it is fully open. Toclose the garage door, the garage door opener 6 runs in the oppositedirection and pushes the garage door outwardly and downwardly, again inguided door section movements, until the garage door is closed, at whichtime the garage door opener is deactuated and the door thereafterremains closed until the garage door opener 6 is again actuated, and thegarage door 1 is again opened. This patent shows the basic manner inwhich most garage doors having hinged sections are opened and closedwhen garage door openers are installed. There are some garage doors thatare not made in hinged sections, but tilt with their tops movinginwardly and their bottoms moving outwardly of the garage, so that theyare stored horizontally, usually with a large part of their lower halvesextending outside the garage itself. The invention is also applicablewhen such other garage doors are being used.

This patent disclosure by Wasson is deficient in giving a clearunderstanding of the connection of the fans and the motor(s) for thefans. In its FIG. 1, it clearly shows, and describes in thespecification, the fan motor 7 as being mounted either on or immediatelyadjacent to the garage door opener 6. Then, somehow that is not at allexplained, that motor 7 is apparently connected by an unnumbered elementshown only as a wavy line, to drive the fans 5 and 8 from its remotelocation. One can only guess how this may be done, but suchpossibilities are not disclosed, and they are not inherent. Therefore,such possibilities are not a fair teaching of anything that evenapproaches certainty. With its wavy configuration, it is not likely thatit is a sheathed wire, such as at one time typically drove automobilespeedometers. The patentee does say, at one point, that the motor 7 maybe located where the exhaust fan itself is located, which is in theupper part of his garage door 1. This is not what is shown in thedrawing, however.

Even if the unnumbered wavy element is an electrical wire or wires, andthe motors are actually integral parts of the exhaust fan assemblies,that wire is obviously very loose, from its point of support at the rearof the garage door opener 6 and the location of the motors at the fans 5and 8 with the garage door being in its closed position as shown inFIG. 1. In that closed-door position, the distance from the motor 7 tothe exhaust fans 5 and 8 is the greatest distance attained between thosetwo points, and the unnumbered element from its connection with theelement 7 and the exhaust fan 5 is shown to be very wavy and free evenin that condition. When the door 1 is raised to the fully open position,the exhaust fans 5 and 8 are moved to be close to the garage door opener6, substantially decreasing the distance between the motor 7 and theexhaust fans 5 and 8. The unnumbered element then would be even muchmore loose and thus be a possible danger. That loose unnumbered elementbecomes a hazard because it has no guidance or arrangement whichprevents it from looping in various directions as the garage door isopened, and much of it may hang down so as to be subject to beingdamaged by any passing object from a vehicle to a ladder being carried,possibly causing a fire hazard to exist, and easily becoming fouled withsomething being carried and extending upwardly to the location of aloose part of the device that is unnumbered. The possible loose loop orloops of the unnumbered element could also interfere with the passage ofindividual persons as they may walk by the one or more vehicles oftenparked in the garage, particularly when they may also be carrying tools,groceries or whatever and have their vision restricted. While thepersons encountering such a loop may not be physically injured, if he orshe wore glasses, they could very easily be knocked off and be difficultto retrieve immediately. This could be dangerous to anyone who has suchimpaired vision that they cannot see without their glasses to avoidinjury as they try to go on through the garage and into the house. Theglasses may even be broken, further inconveniencing that person, as wellas costing him or her to have them repaired or replaced.

BRIEF SUMMARY OF THE INVENTION

The invention may be incorporated into an after-market kit that can beeasily installed in most of the garages built in recent years, or may beinstalled by an experienced installer without any of the aids providedin the kit that such installer would already have. The kit usuallyincludes one or more basic tools that may be needed, but not owned bythe homeowner installer, but may not be needed when a professionalinstaller is used. It also contains detailed directions, and a patternfor openings that are to be cut into the upper and lower panels of agarage door. That being understood, the remainder of this summary willbe directed to the system and its use by a typical installer having allof the needed tools.

The invention is a system for moving ambient outside air into a garageor similar storage area, hereafter being referred to as a garage in thegeneric storage area sense, to remove air that is within the garage. Ithas at least one electrically driven fan installed in an upper part of agarage door, control means for said at least one fan, a power cordoperatively extending from the at least one fan to a fixed source ofpower. There is a force-exerting spring means exerting a continuoustension force on the power cord from the location of the fixed source ofpower to keep the power cord sufficiently taut by exertion of saidtension force so that the power cord has substantially no slack.Eliminating substantially all of the slack in the power cord, its doesnot form any intermediate loop or loops as the garage door is beingopened, or is being closed, keeping the power cord safe from accidentalharm a well as keeping it from becoming a hazard while the garage dooris open or closed.

More particularly, the inventive system removes air in the garage thatis at a higher temperature than the outside air by pushing the cooleroutside air into the garage interior and having that cooler outside aircause the hotter inside air to be forced out of the garage interior. Or,by pushing the hot air in the garage, and pulling the cooler ambientoutside air in. Either mode is equally good, and each one has its ownspecial considerations to be given.

One of the special features of the invention that has not been found inany of the prior art relating to ventilation of an enclosed space suchas a garage. That feature meets the need of a previously unmet need, aswell as the strong desire, for safety purposes as well as neatnesspurposes, to control the physical location of the part of the electricalpower cord extending from the fixed location of the electrical powersource to the fan motor, when that motor is being moved with the garagedoor, whether, yet not in any way interfering with the moving of thegarage door to its open or closed position or remains in one of thoseconditions. The fan, and therefore its motor, being mounted on thegarage door, and the power cord that is extended from its fixedconnection with the power source as the fan motor, is moved further andfurther away from stationary power connection to which the power cord isconnected, when the garage door, having been in the closed position, isbeing moved to its open position. Without this feature of the invention,the loose power cord portion between its connection to a power sourceand its connection to the garage door in the immediate vicinity of theelectrically powered fan or fans installed in the garage door is arelatively loose loop or so of the power cord, often hanging down orpossibly being caught between two of the garage door hinged sectionsthat allow the garage door to be moved from its vertical-when-closedposition to its open position. When it is hanging down below the garagedoor opener mechanism area, it is also a source of possible accidentsand/or injuries that can occur when the garage door is being opened.Using this important feature of the invention, the power cord iscontrolled in its physical aspect when the garage door is in anyposition, and particularly when the garage door is being opened or isopen, so that it does not have a loop formed that tends to hang down andcan become a dangerous hazard to itself, persons in the garage area, andvehicles parked there.

That important feature of the invention is the provision of a power cordtake-up device which prevents the power cord from having loose loops init, particularly when the garage door is open The preferred embodimentof this feature is fully disclosed herein, as well as severalalternative embodiments. The preferred embodiment employs aspring-loaded reel that is mounted on a fixed area that is verticallyclear of the garage door when the garage door is in its open position.The power cord for the fans mounted in the upper panel of the garagedoor is wound on that reel, having its inner end connected to the sourceof electrical power and its outer end connected to a connector box onthe upper part of the garage door, which in turn has electrical wiresconnecting to the fan motors. There is a spring means within the reelthat continually urges the reel in the rotational direction, taking upany slack in the power cord while a closed garage door is being opened.The distance being spanned by the power cord as the garage door is beingmoved to its open position from its closed position becomes shorter andshorter as the garage door is being so moved. After the garage door isstopped, the power cord remains in a taut condition. Thereafter, whenthe garage door is being moved to its closed position from its opencondition, the power cord is being pulled by the movement of the garagedoor and the distance being spanned by the power cord becomes longer andlonger until the garage door is in its closed position. The springstrength of the spring in the reel is such that it allows the power cordto be unrolled from the reel while still keeping sufficient tensionforce on the power cord to keep the slack out of it, and has sufficientstrength to reel in the power cord when the garage door is being movedfrom its closed position to its open position. This constantly-appliedtension to the power cord by the spring in the reel keeps the slack outof the power cord during opening and closing movements of the garagedoor, and also while the garage door is in its open or its closedposition, and none of the power cord is at any time hanging in a loopthat might be engaged by anything or anyone moving with such a loop inits path.

Several alternatives to using a spring-loaded reel to keep the powercord in tension that are within the purview of the invention aredisclosed, but the use of such a reel is definitely the preferred modeof the invention. Two such other alternatives are more simple in that acoil spring which is so arranged that it exerts a spring tension forceon the power cord near where the power cord end that is connected withan electrical power source, and the other end of the power cord issecured to the connection box mounted on the garage door. The fan motoror motors each have electrical wiring connecting them with theconnection box so that they are capable of receiving electrical powerthrough the power cord when the power cord is energized with electricalpower. The spring acts much like a door spring that was so common formany years, but is acting to keep the power cord sufficiently taut thatthere is no adverse lack in it at any time. It is not used to allow orlimit the garage door to be opened and closed and held closed as suchsprings have done for screen doors to houses for many years. The garagedoor opener will open and close the garage door whether or not the powercord is fully connected to provide power to the fan motors. This firstalternative has given rise to another modification where the coil springhas to have its effective length only half the length that the powercord needs when the garage door is being moved between its open andclosed positions. The power cord itself is somewhat longer, and the coilspring has its movable end connected to a pulley having a roller aroundwhich the power cord extends near the location where the power cord isconnected to the electrical power source. The power cord thus forms a180° loop about the pulley roller, and the spring tension is deliveredto the power cord at the that loop, keeping the power cord in tension atall times as does the reel spring and the reel. The advantage to thesetwo alternatives is that they may be less expensive than the springreel. Their disadvantages is that they have to be located well back ofthe point of connection of the power cord with the source of electricalpower, to the full extent of the change in the effective distance of thepower cord between the garage door open and closed conditions for thefirst noted alternative and to ½ the full extent of that change ineffective distance for the second noted alternative. There is a thirdalternative, but it is more expensive than the preferred embodimentusing the spring-loaded reel. It is the provision of the power cordhaving integrally incorporated into it a coil spring for at least asufficient length and spring power to be expandable to the same extentthat the effective power cord length is when the garage door is movedfrom its opened position to its closed position, yet powerful enough tominimize slack to a sufficient extent. This third alternative springarrangement would have some tendency to have some slack in it,particularly as the spring coils retracted as the garage door is movedfrom its closed position to its open position. However, that slightamount of slack would not be sufficient to cause the problem that wouldoccur with the power cord alone, and would still protect the power cordfrom the dangers of the large loop slacks that could occur when no slacktake-up device is used.

The controls of the inventive system include a manual switch that isnormally left on, but can be opened to assure that no electrical poweris delivered to the fan motor when such assurance is desired. At leastone or more controls that sense one or more different conditions withinthe garage are most desirable, and are a common element of the system.These can include a thermostat, that senses the temperature within thegarage, and one that senses the temperature of the exterior ambient airthat might be pulled into the garage. There may also be sensors thatsense gasoline fumes, the presence of either LNG or propane in thegarage atmosphere, smoke, and the level of concentration of carbonmonoxide. When any one or more of these sensed conditions reaches apredetermined level that is considered to be undesirable, the system cancause the fan motor or motors to be energized, yet to still be subjectto the sensing of a higher temperature in the garage than thetemperature outside of the garage to stop the fan motors. The manualcontrol switch can always be used to stop the fan motors or prevent themfrom starting.

Another feature is the provision of sensors that sense the temperaturewithin the garage and the ambient air temperature outside of the garage,and controlling the activation of the exhaust fan motor so that the fanis not energized when the garage temperature is very near to, ordefinitely greater than, the ambient air temperature outside of thegarage, so that the garage interior is not unintentionally heated to aneven higher temperature by warmer ambient air outside of the garage.Once these sensors have comparative readings showing that the air in thegarage is warmer than the ambient air temperature outside of the garage,they may no longer prevent the actuation of the exhaust fan motor.

There are other features found in the system as the system is installedand used, to better cool the interior of the garage and at the same timeremove noxious fumes that are in the garage, instead of having verylittle or no release of hotter air in the garage and no substantialremoval of any of the noxious fumes that may be present in a closedgarage or other storage area. There may, at times the presence ofcertain noxious fumes that become such a potential danger that they haveto be removed as safely as possible. Sensors can be provided for themore dangerous ones of such noxious or dangerous fumes as carbonmonoxide, gasoline and other fuel and oil fumes, as well as more naturalsmells and fumes, such as those from garbage that has been stored insidethe garage, or the possibility of a dead animal in the garage creating avery undesirable stench. Such sensors can cause the fans be actuatedwhether or not the outside air is at a higher temperature than thetemperature is in the garage, or they may be either manually actuated ormanually overridden when it becomes apparent that it is more desirableto circulate outside atmospheric air into and through the garage, eventhough it is warmer than the air in the garage at the time. It is to beunderstood that, when the garage door is open, it is more fully exposedto the outside air and the circulation of the outside air into thegarage and the pushing inside air out, with any fumes or odors it mayhave, is not needed. However, if one wants to circulate the air in thegarage even when the door is open, the fans can still run, and will thenpush or pull the air at the top of the garage downwardly or upwardly sothat the air movements can help the fumes, etc., be more easily blownout by outside wind drafts, so that the problematic inside air is stillevacuated to a great extent.

The system may be installed in a garage or other similar enclosed area,and may be incorporated into a kit form so that all of the necessaryparts, and special tools, are provided so that a person with reasonableskills can easily install it in his or her own garage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation exterior view of a building having a garage withthe garage door being closed. Elements of the invention are readilyapparent such as vents installed in selected areas of the garage door.

FIG. 2 is an elevation view of the building having a garage, shown inFIG. 1, with the garage door being open and the garage being occupiedwith a vehicle.

FIG. 3 shows, in schematic form, controls that are required to provide afunctional system, and also shows additional desirable controls that canbe used in practicing the invention to provide additional safety to thegarage, its contents, and the building with which the garage isassociated.

FIG. 4 is similar to FIG. 3, and is a somewhat simplified schematicrepresentation of various parts of a system embodying the invention.

FIG. 5 is a cross-section view of the garage of FIG. 1, taken in thedirection of arrows 5-5 of that FIGURE.

FIG. 6 is a view of the inner side of the closed garage door, taken inthe direction of arrows 6-6 of FIG. 5, with some of the system that ison the garage door being illustrated.

FIG. 7 is a cross section view similar to the view shown in FIG. 5,showing in a more likely arrangement of the various parts embodying theinvention with the garage door being open.

FIG. 8 is similar to FIG. 7, with the garage door being closed.

FIG. 9 is similar to FIG. 7, showing the use of a length of a tensioncoil spring that is attached to the power cord to keep tension on thatcord at all times, whether the garage door is being opened or closed, orremains opened or closed. The garage door is in the open position.

FIG. 10 is similar to FIG. 9, with the garage door being in the closedposition, and showing that the stretched length of tension coil springhas been substantially increased as the garage door was moved from itsopen position to its closed position, and the power cord is stillsubstantially straight.

FIG. 11 is similar to FIG. 9, using a pulley assembly around the rollerof which the power cord is passed, with a length of a tension coilspring having one end attached to a fixed object and the other endconnected to the pulley assembly. The garage door is in its openposition.

FIG. 12 is similar to FIG. 11, with the garage door in its closedposition.

DETAILED DESCRIPTION OF THE INVENTION

The primary usage of the invention is to remove sufficient warm or hotair from the enclosed interior space such as a garage, and replace itwith cooler outside air so as to keep the interior cooler. The interiorspace may also be subject to vapors that make it uncomfortable to be inan enclosure, and may even be subject, by way of example but not oflimitation, to dangerous gases such as carbon monoxide; fuel vapors suchas gasoline fumes; other types of fumes that are released at times whencertain activities, such as mixing paint, cleaning parts with variouscleaning fluids, etc., are taking place in the enclosed space.Therefore, an at least equally important usage of the invention is toremove such vapors and gases.

While the invention is shown as being installed in a garage that isattached to a residential house, it is also very useful withfree-standing garages or other storage buildings. Therefore, the use ofthe term “garage” in the specification and the claims is to beconsidered to be sufficiently generic to include such garages and otherstorage areas in other types of buildings than just private residences.While, in its preferred embodiment, it is to be also associated with adoor such as are installed with typical garages to the extent that theyare referred to as garage doors, such other buildings often using thesesame types of doors, particularly for storage purposes, whetherindividually or as a group of commercial storage units. The garage dooris illustrated in several of the FIGURES as having several hingedpanels. It is to be understood that such door may also be a solid onethat is mounted so as to be tilted from the vertical, closed, positionto a substantially horizontal, open position. Even a solid door oftenhas several panels arranged from top to bottom.

In garages, for example, there can be gasoline, diesel fuel, propane,liquid natural gas (LNG), and engine exhaust fumes that not only haveundesirable odors, but also have large amounts of carbon monoxide thatcan be life-threatening. There are some of these fumes and odors whenthere is a vehicle therein powered by a gasoline engine, or a dieselengine, or a gas such as propane or LNG. At times, there may be a housetrailer in a garage which is more likely to have tanks of propane or LNGto be used for heating and cooking. Sometimes, such tanks are stored inspecial enclosed storage places, yet are often stored in garages. Thesefumes or vapors are of even more concern when the garage is an integralpart of a larger structure such as an office building or a residentialhome. Those fuels also have different characteristics. For example,propane is heavier than air, and tends to gather in the lower parts ofany restricted area. LNG, on the other hand, is lighter than air, andtends to rise. It will readily disperse when allowed to do so, but isparticularly dangerous when it is still contained in closed spaces.Gasoline evaporates easily, and these fumes are also not only dangerousto breathe, they can easily become ignited when there is sufficientgasoline vapor concentration at the pilot light or other flame source.Once that happens, substantially all of the gasoline vapors in thegarage are so quickly ignited that there is a fiery explosion.

Often, there is a gas water heater also located in a garage. Even if itis not actively heating water, it usually has a small pilot light thatis a small flame that is kept burning at all times, so that when moreheat has to be applied to the water in the heater tank, the pilot lightignites the gas that is allowed to start flowing, and its heating actionheats the water until it has reached a preset temperature, and then thesupply of the gas is cut off, yet leaving the pilot light on. Some gasesused for heating water are heavier than air, propane being an example,and others, such as LNG are lighter than air, and tend to rise to theupper levels when possible. They can be in the garage area if there is agas pipe leak in that area. This can become an exploding bomb when suchgas becomes exposed to a flame such as the pilot light, or when someonelights a cigar, cigarette, or pipe.

It is well known that at least some of these fumes or vapors, andparticularly carbon monoxide, can penetrate into parts of the buildingthat are adjoined to the garage either by door openings, side walls orceilings, or all of those. Such penetration has only too often resultedin the death of someone in such adjoining area. It is very common tohave one or more bedrooms over a garage, with the possibility that fatalresults happen to one or more occupants when the carbon monoxide becomesa fatally high concentration in such a bedroom because of a leakage orpenetration. A vehicle engine may have inadvertently left running atidle while unloading groceries, for example, and after the last load istaken into the main part of the house, the driver simply forgot that theengine was still running as he or she closed the garage door.Tragically, at times, there have even been persons committing suicide byclosing the garage door and purposely letting the engine idle with theproduction of carbon monoxide eventually reaching a fatally dangerouslevel. For these reasons of potential danger or discomfort, it is verydesirable to remove them as much as possible, and to keep the interiorspace of the garage substantially free of all such bad vapors, gases andodors.

Referring now to FIGS. 1, 2, 5 and 6: The building 20 has an attachedgarage 22, defined by the side walls 24 and 26, the front wall 28, theback wall 30, the ceiling 32, and a floor 34. The garage door 36 takesup the opening 38 in the front wall 30. The garage door 36 has severalhinged sections which are panels. There is an uppermost panel 40, anupper panel 48, a lower panel 42 just above a lowest partial panel 44.There are several intermediate panels 46, and there may typically bethree, four, or five ones. In the drawings where a number of panels areshown, this variation in the total number of such panels is recognized.In itself, the precise number of such panels are irrelevant. There justhas to be enough that are not so wide that a panel cannot easily makethe approximately 90° turn from the vertical to the horizontal as therollers at their ends follow the guide rails as the garage door is beingopened, and to do the reverse when the garage door is being closed. Theupper panel 48 may be an intermediate panel as well. It can be eitherthe topmost panel, or one or even two panels below the top edge of thegarage door. Some of these variations are shown in the various FIGURES.The garage upper panel 48 has two motorized fan units 48 and 50installed in it. As better shown in FIG. 5, those fan units haveelectrical power wires 52 and 54 respectively connecting the fan unitsto a connection box 56 mounted on the inner side of a garage door panel.There are two lower vents, 58 and 60, with filters, in the lower garagedoor panel 42. These vents and the fan units are laterally spaced ontheir respective panels. Also shown in FIGS. 2 and 5 is the garage dooropener assembly 62. In FIG. 2, there is an automobile 64, shown as beingparked in the garage 22, as is common. Many garages are made wide enoughto receive two such automobiles, or some are made to receive even more.The building portion 66 that is located over the garage ceiling 32 isshown in FIG. 2 as an attic, but could just as well be a bedroom or astorage area.

FIG. 5 also shows a door 68 through the wall 26, leading to the mainpart of the building 20, Often it is opening through the laundry room ofa typical house. There are two steps 70 so that a person can easily comethrough the door 68 and either step up to the floor level in the houseor down to the floor level of the garage. Other items shown are the reel72, which has the power cord 100 for the fan units 48 and 50 wound onit. It is fixedly mounted on the schematically illustrated base 74 forthe motor door opener and closer 62. That base is held in place bybrackets 76 and 78 that are fastened to the rafters supporting theceiling 32. There is a switch 80 that is wired to control power to thegarage door opener motor 82. If the garage door opener has the garagedoor closed, and switch 80 is momentarily closed by someone who wants itto be opened, the motor 82 of the assembly 62 will be energized to drivethe opener mechanism 84 away from the door 36, and the garage dooropener mechanism will move in the direction to pull the garage door 36open. The mechanism therefore pulls the garage upper panel to cause itto move toward the garage door opener 62. Since each panel is connectedby hinges to its adjacent panel or panels, the other panels follow. Theends of the panels typically have rollers 92 that are received withintracks 94 on each side of the opening occupied by the garage door whenit has been closed. These rollers 92 follow the tracks' verticalsections 96 upwardly and around a curve to the horizontal parts 98 ofthe tracks. When all, or almost all, of the door panels aresubstantially horizontal, the garage door opener motor 82 will bedisconnected from its power source 102 by switch 86 that is controlledby the attainment of the fully open position of the garage door 36. Whenthe garage door is open, and someone desires to close it, that personmomentarily engages the switch 80 again, and the motor of the assembly62 is again energized, this time causing the opener drive mechanism 84to be moved toward the door upper panel 40. The garage door is thenpushed by the mechanism 84 to be moved to its closed position. There isanother switch 88, similar to switch 86, that is controlled by theattainment of the fully closed position of the garage door 36, todisconnect the motor 82 from the electrical power source 102. Thatswitch 88 may also make a closed power cord connection to the electricalpower source 102 so that the fan units 48 and 50 may be energized,assuming that other conditions are such that those fan units are to beenergized upon the closure of the garage door. At the least, theactivation of switch 88 will make it possible to run the fan units 48and 50 because the garage door 36 is fully closed.

The block diagrams of FIGS. 3 and 4 are self-identified to a greatextent. However, each block, and some of the lines joining differentblocks of the diagrams, will be assigned reference numbers and will beexplained in more detail. In each of FIGS. 3 and 4, the block 102represents an electric power source that is in the building 22, anexterior portion of that building being shown in FIGS. 1 and 2. Interioror cross-sectional portions of the building 22, and in particular itsgarage 24, are shown in FIGS. 2 and 5 through 12. This buildingelectrical power source 102 is usually an electrical power box, wired toreceive electrical power from a power company or a generator serving thebuilding. It has either fuses or circuit breakers for various electricalcircuits that serve a building such as a residence or offices or even aseries of commercial storage rooms. Such an electrical power box 102 isoften located in the garage of a residence having no basement, and,therefore, would likely be placed in the garage 24.

In this graphic instance, there are shown only two of the severalseparate electrical circuits in the building 22. One of these circuitsstarts with an electrical wire 104 connecting the power source of block102 with a wall switch 80, which includes a garage-door-opener control,shown as block 108, schematically connected with the switch 80 by wire106, in FIG. 4. That control, when actuated, causes the motor 82 to berotated in one direction to cause the garage door opener mechanism,shown as block 84, to be actuated to open the garage door 36 from itsclosed position shown in FIG. 1 to its open position shown in FIG. 2.The needed direction is sensed by the sensor 116. The garage door 36 isalso shown in its closed position in FIGS. 5, 6, 8, 10 and 12, and isshown in its open position in FIGS. 1, 7, 9, and 11. The garage dooropener mechanism 84 is specifically connected to an upper garage doorpanel, such as the upper panel 40 of the garage door 36. This connection90 is shown in all of the FIGS. 5 through 12. However, again forsimplicity, the wall switch 80 is shown as being on the garage-area sideof the garage side wall 26.

FIG. 4 shows that there is a garage door opener control, represented byblock 108, that has an “on” position and an “off” position. Each timethat switch 80 is activated, it activates the direction control 108,which changes the direction of rotation of the motor 82, depending uponwhether the garage door 36 is open and is to be closed, or vice versa.It is built into the garage door opener assembly.

As shown in FIG. 6, supports 110 are provided for each fan and motorunit 48 and 50. Filters 68 can be installed in one side or the other ofthese supports. These air filters are also supplied in the kit. Thevents 58 and 60 are in the bottom full-sized garage door panel 42, andthe same hole boring tool in the kit can be used for forming theopenings for these vents. Air filters 68 for the vents will also besupplied as parts of the kits they preferably are the same type offilter as those filters 68 for the fan units 48 and 50. The connectionbox 56 has no requirement that any opening or openings be made in a sidewall or the ceiling of the garage. It is easily mounted on the upperpanel 40 of the garage door 36, usually about at a midpoint from thepanel ends, using screws that are provided in the kit. The connectionbox 56 should be positioned below the point 90 where the garage dooropening mechanism 84 has its end in abutting and securely mountedrelation to the garage door upper panel 40, a seen in FIG. 5. There areelectrical wires 84 and 86 extending from the connection box 56, one ofthem going to each of the motors for the fan units. The onlyinstallation requiring some change to the garage door is the need foropenings to be formed through door panels for the fan set or setslocated in the upper door panel 40, and the openings for the filteredvents 58 and 60 installed in the lower, full-width, door panel 42. Thesefilters prevent the entry of insects as well as small animals when thegarage door is closed, whether or not the motorized fan units 48 and 50are operating. When provided in kit form, the invention includes, amongother items, a hole saw blade of the proper size to make the openings inthe garage door. When the hole saw blade is so used, the openings forvents 58 and 60 may be round. The kit may provide other tools that willmake the installation easier and done correctly.

Several of the switches, sensors and controls are shown in FIG. 3, andsome of them are also shown in FIG. 4. There is a wall switch 81 for thefan motors that can be manually operated to be sure that those motorscannot be energized when that switch is in its “off” position. It canusually be left in its “on” position, however, because there are alsoother controls and sensors that may allow or prevent those for runningunder various conditions that are sensed. For example the switch 114 isnormally on, but is connected to receive a signal that turns it off whena sensor senses that the interior temperature in the garage is lowerthan the outside temperature, so that if the fan units 48 and 50 areallowed to run, they would actually cause the garage interiortemperature to go higher, and that is not a desirable result. There is anormally “off” manually controlled switch 116 that can be turned on tobypass switch 114 when someone considers that action to be necessary.There is a block 118 that represents various sensors that can beemployed in the system to sense and generate signals reflecting thecondition sensed. For example, there are sensors 120 and 122 to sensethe inside and outside temperatures of the air respectively in thegarage 22 or similar storage space, and the ambient open airtemperature. It is desirable to introduce outside air into the garageinterior only when it is cooler that the inside air. Therefore there isa comparator 124 that receives the signals representing the twotemperatures, compares the two, and sends a signal 126 to switch 114when the comparison shows that the outside air temperature is higherthan the garage's inside air temperature, and then switch will bechanged to its “off” position so that such an undesirable result cannottake place. The signal 126 can also be sent to a signal board 128 havingvarious signal warning lights that are energized when the particularcondition that they represent exists. In addition to the light 130showing that the outside air temperature is higher than the inside airtemperature. There are other sensors that may be used, and are shown inblock 120. There may be sensors to sense the presence of carbonmonoxide, gasoline fumes, other noxious gases, and noxious odors. Theywill send their generated signals to the comparable warning lights.There are warning lights 132 for carbon monoxide, 134 for gasolinefumes, 136 for other noxious gases, and 138 for noxious odors. It is tobe understood that the system embodying the invention may have all,some, or none of these sensors and signals, depending on the extent thatthe owner of the building 20 wants to have such installations made. Thetemperature control is a major one, because no one would want to heatthe interior air of a garage or storage area when it is desired to keepit cooler. For that reason, the block drawing of FIG. 4 only shows thattype of temperature control. It does show a vent switch, which may beused if movable louvers are provided for the vents 58 and 60 to beclosed when the garage door is closed but the fan units are not to beoperated. Another sensor in block 120 would be a smoke sensor 121,sensing the presence of smoke in the garage. Smoke would be anindication of a fire in there, and such a condition should be sensed,also, and when present should send a signal to switch 114 to prevent thefan units 48 and 50 from being turned on, possibly just fanning thefire, and also to the signal warning light board 128 to energize thesmoke indicator light 140. This signal can also set off an audible alarm142 because the presence of smoke in the garage should be known bysomeone immediately. The audible alarm can be manually turned off by theswitch 142 once the alarm has alerted someone. FIG. 4 also shows a ventswitch 59 which can provide power to open or close the vents 58 and 60,which are in the lower part of the garage door. This will furtherprevent any intrusion of debris, dust, insects and small animals whenthe door is closed and the fans in the upper panel of the garage doorare not operating.

FIGS. 7 and 8 show the use of the reel 72 for the power cord 100. InFIG. 7, the garage door 36 is shown in its open position. The power cord100 is therefore wound up on the reel so that all of it not so wound isin tension so that it cannot form a loose loop. In FIG. 8, the garagedoor 36 is shown in its closed position. The power cord 100 is extendedout in a substantially straight line, because it is still in tensionfrom the reel 72 to the connection box 56. It cannot form any looseloops that would hang well below that straight line, and there is nodanger from such loose loops. When the garage door 36 is returned to theopen position, the spring in reel 72 also retracts the power cord byrewinding it on the reel, keeping sufficient tension on the power cord100 so that it does not form any loose loops.

FIGS. 9 and 10 show the substitution of a tension spring 200 with oneend of it secured to a fixed support such as the back wall 28 of thegarage, and the other end connected to the power cord 100 spaced aneeded distance from its end where it is plugged into a receptaclereceiving electricity from the electrical power source 102 so that italways remains plugged in as the power cord is moved as the garage door36 is moved from its open position to its closed position, shown in FIG.10. FIG. 10 also shows the tension spring 200 stretched a distance thatis equal to the distance that the end of the power cord connected to theconnection box 56 moves when the garage door is moved from its openposition to its closed position. When the garage door 36 is returned tothe open position, the spring 200 also retracts, keeping sufficienttension on the power cord 100 so that it does not form any loose loops.

FIGS. 11 and 12 show a modification of the spring setup in FIGS. 9 and10. The spring 300 is considerably shorter than spring 200. One of itsends 306 is connected to a suitable fixed element schematically shown aselement 308. The movable end 310 of spring 300 is connected to the yoke312 of a pulley 302, which has a roller 304 rotatably mounted within theyoke 312 so as to be rotatable. The power cord 100 is located so thatits movements, one movement of the rotatable movement of the pulleyroller in one direction being obtained by the force of the spring 300 asthe door is being opened, and the other movement, in the oppositedirection, being caused by the force of the spring as the door is beingclosed. The power cord has about a 180° bend in it that bends around thepulley roller. That bend allows the pulley yoke 312, and therefore theend of spring 300, to have to move only ½ the distance that the end ofspring 200 in FIGS. 7 and 8 has to move during each door opening andeach closing movement. Otherwise, it works in the same manner as doesspring 200. It also keeps some tension on the power cord 100, whetherthe garage door 36 is open as shown in FIG. 11 or is closed as shown inFIG. 12. That continuous tension exerted on power cord 100 prevents thatpower cord from falling down in one or more loose loops as the garagedoor 36 is being moved from its closed position to its open position,thus eliminating a potentially dangerous condition.

1. A system for operatively moving ambient outside air into a garage orsimilar storage area, hereafter being referred to as a garage in thegeneric storage area sense, and for operatively removing air that iswithin the garage while replacing that air with air from outside thegarage, said system having first vent means set in the upper part of agarage door and second vent means set in the lower part of the garagedoor, at least one electrically driven fan installed in at least one ofsaid vent means sets, control means for controlling the operation ofsaid at least one fan, and a power cord operatively extending from saidat least one fan to a fixed source of power, and a force-exerting meansexerting a tension force on the power cord from the location of thefixed source of power to keep said power cord sufficiently taut byexertion of said tension force so that said power cord has substantiallyno slack so that its does not form any intermediate loop or loops as thegarage door is being opened, or is being closed, keeping said power cordsafe from accidental harm a well as keeping it from becoming a hazardonce the garage door is open.
 2. The system of claim 1, said systembeing more particularly for removing air in the garage interior that isat a higher temperature than the temperature of the air outside of thegarage by pushing cooler outside air into the garage interior throughone of said vent means and having that cooler outside air that is pushedinto the garage interior through the other of vent means then causinghotter inside air to be pushed out of the garage interior.
 3. The systemof claim 2 in which the outside air is pushed into the garage interiorby said at least one fan located at least vertically closely adjacent tothe top of the garage door and the garage inside air is pushed out ofthe garage interior through the vent means adjacent to the bottom of thegarage door, the garage door having vents at least horizontally closelyadjacent to the bottom area of the garage door for that purpose.
 4. Thesystem of claim 1, said system being more particularly for removing airin the garage that is at a higher temperature than the outside air bypulling hotter inside air through one of said vent means set to theoutside of the garage interior with said at least one fan located in oneof said vent means and, because the air pressure in the garage is thenless than the outside air pressure, to also pull cooler outside air intothe garage interior through the other of said vent mean set, therebyhaving the effect of having cooler air in the garage interior.
 5. Thesystem of claim 1, said force-exerting means being a spring means thatcontinually exerts a tension force on said power cord tending to movesaid power cord.
 6. The system of claim 2 which has a reel that ismounted on a fixed area that is vertically clear of the garage door whenthe garage door is in its open position, said power cord being wound onsaid reel and said reel having said spring means therein which urgessaid reel rotationally toward taking up any slack in said power cordwhile the garage door is being opened and the distance spanned by saidpower cord becomes shorter, to hold said power cord with any slack in itbeing taken up, and to allow the power cord to be unrolled from saidreel when the garage door is being closed while still keeping sufficienttension force on said power cord to keep the slack out of said powercord.
 7. The system of claim 1, said power cord having said spring meansformed as a coil spring integrally located therein which is normallyclosely coiled when in its free position, and which is stretched tospread the coils thereof increasingly further apart to increase theeffective length of said coil spring and allow said power cord to beconcurrently stretched sufficiently to maintain its power relation tothe at least one fan and the power source when the garage door is beingmoved to its closed position from its open position, and to retract saidpower cord by decreasing the spacing of the coils of said coil springand thus decrease the effective length of the power cord, keeping saidpower cord from forming one or more loose loops during the opening ofthe garage door and while the garage door remains in its open position.8. The system of claim 1 in which said spring means is a coil springhaving a short natural, unstretched, length and having a first endoperatively attached to a fixed device and a second end operativelyattached to said power cord near said power cord end that iselectrically connected with an electrical power source, said coil springbeing stretched from its natural unstretched length to at all times beapplying a tension force to said power cord and being capable ofincreasing its effective length while maintaining a tension force onsaid power cord as said power cord is extended in its overall effectivelength extending from said power cord end operatively connected with theelectrical power source, so that there is no loose loop of said powercord formed when the garage door is being opened, keeping said powercord from being either a danger to itself or to something else that maybecome engaged by any such loop if such a loop is allowed to be formedwhile the garage door is opening.
 9. A system in which an enclosed spacesuch as a garage or other storage area has outside atmospheric airreplacing the atmospheric air in said garage or other storage area byuse of fan means moving the outside air into the interior of the garageor other storage area and moving the inside air out of said garage orother storage area, said fan means being installed on a garage door thathas a closed position and an open position, and a power cord for saidfan means having a first end and a second end, said power cord beingused in that system wherein said first end thereof is relatively fixedand the said second end thereof is movable for a distance from a firstposition that is near said first end to a second position that issubstantially further away from said relatively fixed first end when thegarage door is moved from its open position to its closed position, andsaid power cord second end being moved back toward said power cordrelatively fixed first end when the garage door is being moved from itsclosed position to its open position, said power cord being capable ofloosely forming one or more loose loops when said second end is beingmoved back toward said first end should no tension force being appliedto said power cord, and means keeping said power cord sufficiently tautto prevent the formation of one or more loose loops, said means keepingsaid power cord taut being a spring-loaded arrangement tensionallypulling on said power cord as the garage door is being opened to keepsaid power cord from becoming loose between said ends so as to form oneor more loose loops that are potentially dangerous.
 10. The system ofclaim 9, said means keeping said power cord sufficiently taut to preventthe formation of one or more loose loops, said means keeping said powercord taut being a reel having a coil spring, said reel being mounted ona substantially fixed area that is clear of the garage door when thegarage door is in its open position, said power cord being wound on saidreel and said reel coil spring therein which urges said reelrotationally toward taking up any slack in said power cord while thegarage door is being opened and the distance spanned by said power cordbecome shorter, to hold said power cord with any slack in it being takenup, and to allow the power cord to be unrolled from said reel when thegarage door is being closed, still keeping the slack out of said powercord.
 11. The system of claim 9, said means keeping said power cordsufficiently taut to prevent the formation of one or more loose loops,said means keeping said power cord taut being a coil spring integrallylocated in said power cord which is normally in its free positionclosely coiled, and which is stretched to increase the effective lengthof said coil spring and allow said power cord to stretch sufficiently tomaintain its power relation to the at least one fan when the garage dooris moved to its closed position from its open position, and to retractsaid power cord by decreasing the effective length of the power cord,keeping said power cord from forming one or more hanging loops duringthe opening of the garage door and while the garage door remains in itsopen position.
 12. The system of claim 9, said means keeping said powercord sufficiently taut to prevent the formation of one or more hangingloops, said means keeping said power cord taut being a coil springhaving a short natural length and having a first end operativelyattached to a fixed device and a second end operatively attached to saidpower cord near said power cord end that is electrically connected withan electrical power source, and being capable of increasing itseffective length as the power cord is extended in its overall effectivelength extending from said power cord end operatively connected with theelectrical power source, so that there is no loose loop of said powercord formed when the garage door is being opened, keeping said powercord from being either a danger to itself or to something else that maybecome engaged by any such loop if such a loop is allowed to be formedwhile the garage door is opening.
 13. A kit for installing a ventilationsystem to be used in conjunction with an enclosed space such as a garagethat is opened to the outside atmosphere by opening a door that is movedvertically and horizontally from its closed position to its openposition by a door opener when access to that space is needed, and thedoor is moved from its open position to its closed position so as toclose the enclosed space from the outside atmosphere when the dooropener is actuated to move the door from a substantially horizontalposition to a substantially vertical position, said kit comprising: atleast one fan having an electric motor, said fan with its motor beingmounted on a support member for installation in an opening in the upperpart of the door; a device for creating the opening in the upper part ofthe door through which said at least one fan and said support member forsaid fan is mountable; said at least one fan motor selectively runningsaid fan in accordance with sensed conditions of the atmosphere withinthe closed space and the atmosphere outside of the enclosed space, andwhen running with the door closed normally causes cooler air from theoutside being brought into the interior of said closed space so that theinterior of said closed space is cooled; a connector box adapted to besecured to the door, said connector box having an electrical powerreceptacle thereon and at least one wire extending therefrom and leadingto said fan electrical motor to provide electrical power thereto; apower cord having one end adapted to be connected to an electricalcurrent power source and its other end adapted to be operativelyconnected to said at least one fan electrical motor through saidconnector box, the overall length of said power cord being sufficient tomaintain such connection between the electrical current power source andsaid connector box when the door is in its closed position and torequire a lesser overall length when the door is in its open position,leaving a middle part of said power cord likely to become a hazardbecause it may become temporarily located well away from a substantiallyhorizontal and straight line between said power source and saidconnector box when the door is in its open position, and tensioningmeans operatively acting on said power cord to tension said power cordand thus maintain said power cord location to be on a substantiallystraight line extending between and beyond said power source and to saidat least one fan motor connector box, once said kit is installed, sothat there is no loosely located part of said power cord between saidelectrical power source and said connector box creating a possiblehazard if it were to be loosely located.
 14. The kit of claim 13, inwhich said tensioning means operatively acting on said power cord totension said power cord includes spring means adapted to tension saidpower cord to substantially eliminate the possibility of said power cordhaving a loose section that may be a hazard when said power cord isattached to an electrical power source and the connector box for said atleast one fan motor with a substantially longer effectively-requiredpower cord length when said than the minimum power cord effective lengththat exists when said door is fully open.
 15. The kit of claim 13, saidspring means including a reel that is adapted to be mounted on a fixedarea that is clear of the garage door when the garage door is in itsopen position, said power cord being wound on said reel and said reelhaving said spring therein which urges said reel rotationally towardtaking up any slack in said power cord while the garage door is beingopened and the distance spanned by said power cord become shorter, tohold said power cord with any slack in it being taken up, and to allowthe power cord to be unrolled from said reel when the garage door isbeing closed, still keeping the slack out of said power cord.
 16. Thekit of claim 13, said power cord having a coil spring integrally locatedtherein which is normally in its free position closely coiled, and whichis stretched to increase the effective length of said coil spring andallow said power cord to stretch sufficiently to maintain its powerrelation to said at least one fan when the garage door is moved to itsclosed position from its open position, and to retract said power cordby decreasing the effective length of the power cord, keeping said powercord from forming one or more loose loops during the opening of thegarage door and while the garage door remains in its open position. 17.The kit of claim 13 in which said tensioning means is a coil springhaving a short natural unstretched length and having a first endoperatively attached to a fixed device and a second end operativelyattached to said power cord near said power cord end that iselectrically connected with an electrical power source, and beingcapable of being stretched, increasing its effective length as the powercord is extended in its overall effective length extending from saidpower cord end operatively connected with the electrical power source,so that there is no loose loop of said power cord formed when the garagedoor is being opened, keeping said power cord from being either a dangerto itself or to something else that may become engaged by any such looseloop if such a loose loop is allowed to be formed while the garage dooris opening.
 18. The kit of claim 13, further including control means forselectively electrically connecting and disconnecting said power cordfrom the electrical current power source; said control means comprising:a first thermostat adapted to sense the temperature of the air in theenclosed space, and a second thermostat adapted to sense the temperaturein the outside air immediately beyond the door; said thermostats beingso connected to control the electrical connection between saidelectrical power source and said at least one fan motor to keep saidelectrical power source disconnected from said at least one fan motorwhen the temperature inside said enclosed space and sensed by said firstthermostat is less than the outside air temperature sensed by saidsecond thermostat, and an “on-off” switch connected to permit theelectrical connection between said electrical power source and said atleast one fan motor only when the door is at least substantially closed.19. The kit of claim 18, said control means also including a garagedoor-position sensor switch which includes an “on-off” switch positionedso that said door-position sensor switch is in its “on” position onlywhen and while said door is at least substantially closed; said “on-off”switch having a manual “off-on” override for overriding said switch's“off” position when the electrical connection between and saidelectrical source and said at least one fan motor is desired even whenthe door position is not substantially closed, and for overriding saidswitch's “on” position when it is desired that the electrical connectionbetween said electrical source and said at least one fan motor beconnected even though the sensed door position is sensed as being moreopen than other than being substantially closed.
 20. The kit of claim17, said control means also including a first manual override switch forsaid thermostats so that said thermostats can be rendered ineffective tomanually interrupt the electrical connection between said electricalsource and said at least one fan motor, and that electrical connectioncan selectively be interrupted and established independently of saidthermostats.